Nuclear Alert in Japan

Updates from The Guardian … here

8.37pm GMT: The Associated Press has news of US workers at the damaged Fukushima nuclear power reactor in Onahama city, about 270km northeast of Tokyo:

Pineville, Louisiana, resident Janie Eudy said her husband, Danny, was working at Fukushima No 1 when the earthquake struck. After a harrowing evacuation, he called her several hours later from the parking lot of his quake-ravaged hotel.

He and other American plant workers are “waiting to be rescued, and they’re in bad shape,” she said in a telephone interview.

Danny Eudy, 52, a technician employed by Pasadena, Texas-based Atlantic Plant Maintenance, told his wife that the quake violently shook the plant building he was in. “Everything was falling from the ceiling,” she said.

Eudy told his wife that he and other workers were evacuating the plant when the tsunami swept through the area, carrying away homes and vehicles. They retreated so they wouldn’t get caught up in the raging water.

“He walked through so much glass that his feet were cut. It slowed him down,” she said.

9.20pm GMT: More unsettling news from the Fukushima No 1 nuclear power reactor in Onahama: the plant’s operator Tepco says that radioactive substances “could have already been released” from the damaged reactor, while Japan’s prime minister Naoto Kan is saying that residents within 10km of the plant must leave the area.

Kan was set to visit the plant this morning.

Previously, the area of three kilometres around the reactor had been evacuated, while those within 10km were told to stay indoors.

Radiation has been more than eight times the normal level according to a monitoring post near the main entrance to the plant, the Japanese industry ministry’s nuclear and industrial safety agency said.

9.43pm GMT: The level of radiation in the control room of the No 1 reactor of the damaged Fukushima Daiichi nuclear plant is “1,000 times higher than normal,” according to Japan’s nuclear and industrial safety agency, visiting the site.

According to the Kyodo news agency: “The discovery suggests radioactive steam could spread around the facility operated by Tokyo Electric Power Co.”

10.12pm GMT: An AP news alert:

Japan says radiation levels surged outside nuclear plant, expands area subject to evacuation.


10.34pm GMT: The damaged Fukushima Daiichi nuclear reactor has already been leaking radiation outside the plant, confirms Japan‘s nuclear safety agency and the operator, the Tokyo Electric Power company.

Compared with the government briefing last night that everything was fine, that’s a turn around.

According to AP, the continued loss of electricity has delayed the planned release of radioactive vapor from inside the reactor to ease pressure. Pressure inside one of the reactors had risen to 1.5 times the level considered normal.

10.45pm GMT: Now there are reports from nuclear plant operator Tepco that the Fukushima No 2 plant has lost cooling to three of its reactors.

It was one reactor in the Fukushima No 1 plant that had been the cause for concern earlier – so this news is certainly unwelcome.

11pm GMT: The Kyodo news agency is reporting that the Japanese government is ordering Tepco to open valves on the Fukushima No 1 reactor to release pressure.

11.34pm GMT: Meanwhile, Japan‘s nuclear safety agency is set to issue an unprecedented order for Tepco to open a valve at the damaged Fukushima Daiichi nuclear power plant to release pressure, as we reported earlier.

The good news is that the 3,000 residents in the initial evacuation radius have been safely removed.

11.29pm GMT: This is more chilling news from Kyodo:

The cooling system failed at three reactors of the quake-hit Fukushima No. 2 [Daini] nuclear power plant Saturday, the operator Tokyo Electric Power Co. said.

The company, which has already scrambled to deal with radiation leaks at its Fukushima [Daiichi] No. 1 plant, notified the industry ministry that the failsafe system at the No. 2 plant stopped functioning as the temperature of coolant water has topped 100 C.

11.47pm GMT: In the comments, many people are asking what the implications of the nuclear reactor power failure is. Given how little we are being told by Tepco and the Japanese government, it’s hard to say. The increase in background radiation near the plant isn’t dangerous at this point, but of course that could change.

Reuters has a piece explaining what happens when a reactor loses coolant:

When all sources of power fail like at the Fukushima Daiichi plant, coolant begins to boil off, exposing the fuel rods. It would likely take several hours to boil off enough coolant before the core is hot enough to damage it.

If the fuel rods became damaged they would release radioactive material into the remaining coolant.

– Hours beyond that the metal surrounding the ceramic uranium fuel pellets could potentially start melting if temperatures reach well beyond 1000F as occurred at Three Mile Island. The ceramic fuel pellets would not melt until temperatures reached about 2000 degrees F.

– Hours after the fuel rods started to melt, the heat could potentially melt through the reactor vessel, which is made of high tensile steel four to eight inches thick

– It would take even more time before the containment fails, which could result in radioactive releases to the environment. The containment is an air tight steel or reinforced concrete structure with walls between four to eight feet thick.

As the Three Mile Island accident showed, operators can regain control of the situation if they can get the coolant flowing again.

11.55pm GMT: For informed commentary on the nuclear reactor problems in Japan, those of you with Twitter accounts should follow @arclight who appears to know the stuff.

12.12pm GMT: A number of readers have raised Chernobyl in comparison to the events at the Fukushima plants.

The Chernobyl disaster was caused by a power surge and subsequent explosion that caused a fire. The situation in Fukushima (from what we know) is power failure shutting down reactor coolant systems, and the failure of back-up generators.

12.20pm GMT: Scientific America is on the case with an excellent explanation of what’s going on at the Fukushima nuclear plants:

Tokyo Electric Power confirmed that pressure had been rising inside reactor No. 1 at its Fukushima Daiichi nuclear power plant on the northeast coast, one of the largest nuclear power plants in the world. That means cooling water is not getting to the reactor core, causing a build up of steam inside the containment vessel. The problem, according to Japanese media reports, is a loss of grid electricity to run the pumps that bring in cooling water. The backup diesel generators that are supposed to provide emergency power in that case are out of order, according to the Japan Atomic Industrial Forum, but replacements were being taken to the plant.

Scientific America’s David Biello has an interview with Scott Burnell, public affairs officer at the US Nuclear Regulatory Commission:

What happens when a reactor gets disconnected from the grid?

There are emergency diesel generators. You also have a battery system to keep instruments running, but that can also provide power to safety systems [which prevent a meltdown by cooling the reactor core]. It’s all meant to provide defense in depth. First you rely on the grid. If the grid is no longer available, you use diesel generators. If there is an issue with the diesels, you have a battery backup. And the batteries usually last long enough for you to get the diesels going.

12.25pm GMT: Now an official from Japan‘s powerful trade ministry is telling news organisations that Tepco is “also considering releasing pressure” at the Fukushima Daini nuclear plant.

The government has also just ordered the evacuation of a three kilometre radius around Fukushima Daini plant – following the previous evacuation order of a 10km radius around Fukushima Daiichi.

12.31pm GMT: Given the events at the Fukushima plants, other useful Twitter accounts worth following on the subject: the International Atomic Energy Agency @iaeaorg and the US Nuclear Energy Industry @N_E_I (and yes I know they are a lobbying outfit for the industry but they are following events in Japan).

6.55am: GMT While we wait for more news from the press conference by Japan’s Nuclear and Industrial Safety Agency, a quick update on events:

Workers have successfully vented gas from the reactor, reducing pressure, but Japanese media report that prime minister Naoto Kan has not ruled out a possible radiation leak from the No. 2 reactor.

7.15am: GMT A fuller read on the nuclear situation is now up here.

7.52am: GMT Japanese media reporting that explosion heard at TEPCO’s Fukushima Daiichi plant around 0630 GMT – more soon

7.56am: GMT Justin McCurry in Japan says explosion reported at Fukushima Daiichi (No 1) reactor at 15:36 local time (06:30GMT). TV footage shows smoke rising from plant.

8.35am: GMT The nuclear plant’s operators say four people were injured in the explosion, Kyodo news agency reports.

NHK is advising people in the Fukushima area to stay inside, close doors and windows and turn off air conditioning. They have also been advised (presumably if caught outside?) to cover their mouths with masks, towels or handkerchiefs

8.45am: GMT Justin McCurry says television footage is showing the exposed frame of one of four buildings housing reactors. The external panelling appears to have been blown away, but no flames or smoke are visible almost two hours after the blast. Officials in Fukushima prefecture said the cause of the explosion is being investigated.

9.14am: GMT Reuters reports that the UN’s nuclear watchdog – the International Atomic Energy Agency – is urgently seeking information on the situation at the power plant.

Chief cabinet secretary Yukio Edano has confirmed a radiation leak, but it is not clear if he was referring to the aftermath of the blast or to earlier reports of high readings in the area.


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